Airspeed Limitations and Indicator Markings

The airspeed limits of the Seneca III and the way they are painted on the airspeed indicator. Two radial lines on the dial belong to flight on one engine: the red line at V_MCA and the blue line at V_YSE.

At a glance

• V_A (4407 lb)135 KIAS
• V_A (3205 lb)114 KIAS
• V_NE205 KIAS
• V_NO166 KIAS
• V_FE115 KIAS
• V_LE130 KIAS
• V_LO (extending)130 KIAS
• V_LO (retracting)108 KIAS
• V_MCA66 KIAS
• V_YSE92 KIAS

Airspeed limitations

• Design maneuvering speed V_A — 135 KIAS (137 KCAS) at 4407 lb (1999 kg) gross weight; 114 KIAS (115 KCAS) at 3205 lb. Make no full or abrupt control movements above it.

• Never exceed speed V_NE — 205 KIAS (203 KCAS). Do not exceed it in any operation.

• Maximum structural cruising speed V_NO — 166 KIAS (165 KCAS). Do not exceed it except in smooth air, and then only with caution.

• Maximum flaps extended speed V_FE — 115 KIAS (113 KCAS).

• Maximum gear extended speed V_LE — 130 KIAS (130 KCAS).

• Maximum landing gear extending speed V_LO — 130 KIAS (130 KCAS).

• Maximum landing gear retracting speed V_LO — 108 KIAS (109 KCAS).

• Air minimum control speed V_MCA — 66 KIAS (65 KCAS): the lowest airspeed at which the airplane is controllable with one engine operating at takeoff power and no flaps.

• One engine inoperative best rate of climb speed V_YSE — 92 KIAS (91 KCAS).

CAUTION — Maneuvering speed gets lower as the airplane gets lighter, because aerodynamic forces become more pronounced. Linear interpolation may be used for gross weights in between. Do not exceed maneuvering speed in rough air.

The gear has two operating limits: it may be lowered at up to 130 KIAS but must be raised at no more than 108 KIAS. Two other printed sources give maneuvering speed as 136 KIAS — the instrument panel placard, which states it at 4407 lb, and the emergency checklist's list of airspeeds for safe operation.

Airspeed indicator markings

• Red radial line (never exceed): 205 KIAS

• Red radial line (one engine inoperative air minimum control speed): 66 KIAS

• Blue radial line (one engine inoperative best rate of climb speed): 92 KIAS

• Yellow arc (caution range, smooth air only): 166 to 205 KIAS

• Green arc (normal operating range): 67 to 166 KIAS

• White arc (flap down): 64 to 115 KIAS

Figure: Airspeed indicator markings (redrawn).

Each arc ends at a limit from the table: the white arc tops out at V_FE, the green arc at V_NO, and the yellow arc at V_NE.

Check yourself

• What is V_A at 4407 lb and at 3205 lb, and why does it change with weight?

• What are the two V_LO values, and which one applies to raising the gear?

• What does the lower red radial line mark, and at what speed?

• Which speed is marked by the blue line?

• Which limits sit at the top of the white, green and yellow arcs?

Study aid — always fly your aircraft's current AFM/POH.